title: [Response of chickens to the addition of yeasts of various origin to broiler feed mixtures].
abstract: The bioassays were aimed at testing the safety of complete starter and fattening broiler feed mixtures containing yeasts produced from sulphite liquors, synthetic ethanol and sulphite-ethanol substrate. The yeasts were included in the formulation of the mixtures at a 6% and 10% concentration and were enriched with methionine and B12. The following can be stated on the basis of the obtained results and evaluation of the over-all health state of the chickens: the effort to demonstrate a direct toxic effect of the tested yeasts on the chick organism by biochemical and haematological parameters failed,--at a 10% yeast concentration a tendency to a decreasing of chick live weight occurred towards the end of the experiment, irrespective of the origin of the yeasts,--the haemorrhages testifying to haemorrhagic diathesis, observed in different stages, might be caused by increased oxigenation of vitamin K, as suggested by our experience and by literary data: some role might also be played by stress from coccidiosis, which reduces the level of this vitamin,--the haemorrhages were more pronounced in the groups with a 10% concentration of yeasts,--although no direct toxic effect of yeasts was clearly demonstrated, it can be recommended on the basis of patho-anatomic findings that the yeasts should not constitute more than 6% of the volume of broiler mixtures and that the content of vitamin K should be increased to 400 mg per 100 kg.
mesh_terms: D000821:Animal Feed / Q000009:adverse effects*; D000818:Animals; D002645:Chickens; D006474:Hemorrhagic Disorders / Q000209:etiology / Q000662:veterinary*; D011201:Poultry Diseases / Q000209:etiology*; D015002:Yeast, Dried / Q000009:adverse effects*
vernacular_title: Odezva organismu kurat na pridávání kvasnic různé provenience do brojlerových smĕsí.